Do you know at what temperature you turn on your heating? For us, it’s 10 degrees, and it’s measured inside, not outside.
Our heating works very well, by the way. The problem is that it mostly heats the storage compartments.
There you go, in two sentences, the exact situation we’ve been living in for five years. A original gas Truma, the one from 1999, still functional after twenty-seven years, which provides both heating and hot water, and part of the heat is lost along the way because the distribution ducts are pierced. It’s this kind of detail that you won’t find in any guide, and yet it’s exactly what happens with an old vehicle.
Add to that a second confession: we don’t turn it on that often because our real heating is geography. So we might as well write the honest article rather than the comparative one.
How a gas Truma heater works
The principle is simple, and that’s what makes it durable. Gas arrives at a burner, ignited by an automatic igniter powered by batteries, and this combustion occurs in a completely sealed chamber relative to the living space. The burnt gases exit outside through a chimney, and the combustion air comes from outside as well. At no point do you breathe what is burning.
Surrounding this chamber is a heat exchanger. A fan pushes the air from the living space against the exchanger, the air heats up, and it returns to the vehicle through distribution ducts that run under the furniture to vents distributed throughout the living area. On a combined unit, the same burner also heats the water tank of the boiler.
Three practical consequences. One, the device needs electricity, not for heating, but to run the fan. Two, the temperature rise is quick because it is forced air, not inertia. Three, and this is the blind spot: the whole performance depends on the ducting, which is neither inspected, nor visible, nor ever mentioned in an advert.
One British caveat on that word “inspected”. The MOT never looks at any of this, and there is no compulsory gas check for a privately owned motorhome in the UK: the thing that would catch a sick heater is the voluntary habitation service, or a Gas Safe engineer with the LPG endorsement. It is worth knowing that this is a matter of choice here, because it is not everywhere. In Germany the gas system check, the G 607, comes round every two years and is genuinely enforced, and Italy runs its own periodic check on the installation. If you are heading over there for a season, that is a document worth having before you go rather than after someone asks for it.
How a Truma gas combination heater warms a motorhome
A flame enclosed in a sealed chamber, a heat exchanger, a fan, and ducts that distribute. Everything hinges on the last link.
| Step | What happens | What can fail |
|---|---|---|
| 1. The bottle | Propane reaches the unit through a regulator. Nothing electric in this part. | Butane stops vaporizing around 0 °C. In winter, it's propane or nothing. |
| 2. The burner | The flame lives in a sealed chamber. Combustion air comes from outside, burned gases go outside. | Weak ignition batteries, blocked chimney. Two silly failures that put the device in safety mode. |
| 3. The heat exchanger | Heat transfers to the cabin air and, in a combination, to the 10-liter water tank. | This is the part that lasts. On a 1999 vehicle, it still works. |
| 4. The fan | It pushes cabin air against the heat exchanger. It is the only one that consumes 12 V. | Without electricity, no distribution. The burner can run, but the heat goes nowhere. |
| 5. The ducts | Flexible accordion conduits bring hot air to the outlets distributed throughout the cell. | The weak link, and ours. A split duct heats a storage compartment, and nothing indicates it. |
Pierced ducts, the failure no one talks about
I clarify, because confusion is easy: these are not the ducts of the Truma itself. These are the distribution ducts, made of cardboard, accordion-shaped, those that lead from the device to the hot air vents in the living space. On a vehicle of this age, they wear out, they crack, they come loose.
The result is quite comical when you’re not facing the bill: sometimes the heat is more in the storage compartments than in the living space. The burner does its job, the fan does its job, and part of the hot air is delivered into a shoe compartment.
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Read moreWhat it really consumes
This is the figure that no one provides, and I understand why: there is no single answer. What we can provide is a range and a method.
A gas heater in a motorhome consumes around 150 to 500 grams of gas per hour depending on the model and the power required. For devices in the classic range, we’re talking about approximately 150 g/h for a small model and 225 g/h for a larger one at full power.
And the variable that matters most is not the outside temperature, it’s the actual operating time of the burner. A heater set on a thermostat does not run continuously; it turns on, turns off, and turns back on. Two identical vehicles on the same night can consume anywhere from half to double depending on the setting, insulation, wind, and how many times you open the door.
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Read moreGas, diesel, electric: what I can say and what I can’t
I have never lived with a diesel heater. So I’m not going to tell you which is better because I don’t know, and the people who tell you without having experienced it, you’ve already read them. What I can do is lay the figures side by side.
About 150 to 500 g/h. Silent, very little maintenance, no complicated electronics, and it works in a location without electricity. It’s also the only solution that shares energy with cooking and hot water. The downside: you have to carry bottles, and refueling rules change at each border.
Between 0.1 and 0.4 liters per hour in normal use, up to about 0.49 L/h at full load on high-power models. It draws from the engine’s tank, so no more bottles to manage, and fuel is available everywhere. However, you need to account for its electrical consumption, around 15 to 55 watts in operation, which represents about 45 amp-hours over a full day at maximum. In Britain the unit alone is £700 to £1,400 for a Webasto or an Eberspächer depending on output, and fitting is quoted in hours, typically eight for a 2 kW and ten for a 4 kW, so a professional supply-and-fit lands well north of the unit price. And there is real burner noise.
Zero combustion, zero maintenance, zero odor, and instant control. But it only exists when plugged into the 230 V of a campsite or equipped area. On its own, it’s out of the question: heating electrically on battery drains a complete solar setup in one evening. It’s a site heater, not a travel heater.
The small 12 V blowers found at low prices do not heat a volume; they defog a windshield. Physics is stubborn: a few hundred watts do not replace several kilowatts, and the battery doesn’t handle it well. This is not a heating solution; it’s a cabin accessory.
Our actual usage, honestly quantified
The rule in our house has never changed: we turn it on as soon as it reaches 10 degrees inside the motorhome. Not outside, inside. That’s the only threshold we follow, and it’s quite low because below that, we can’t work properly.
Then, the rhythm is as follows. We turn it off at night, unless it’s really cold. We turn it back on in the morning when we wake up. And sometimes during the day, when the temperature doesn’t rise. It’s not about ecological virtue; it’s that sleeping with a fan that kicks in every twenty minutes is not restful, and a duvet does the job for free.
What helps a lot, and goes against the prevailing discourse on old vehicles: nine square meters heats up very quickly, even in an old motorhome. The question is not about having a powerful device; it’s about having a small volume and knowing how to maintain it.
I'm Xavier
I write up what we learn on the road, from the gear we wear out to the paperwork that lets us live off it. Without dressing it up.
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What we do before turning it on
Everyday actions
Layers of clothing, and especially thick socks, because the cold in a motorhome rises from the floor before anything else.
Sleeping bags opened wide and used as blankets. That’s our real night solution; it costs nothing, and it often makes nighttime heating unnecessary.
And humidity, which should never be underestimated: it’s what makes the air feel even cooler. Dry air at 16 degrees is more comfortable than humid air at 18.
Carpet, our best insulator
Édouard has a carpet on the floor, inherited from the previous owner, and I thought it would be a bad idea. It’s the opposite: it really insulates. As soon as it starts to get a bit cooler, it’s still the best.
The downside is real, and you have to accept it: it’s very hard to keep clean. Hence an absolute rule in our house, no shoes inside. It’s not a cleanliness obsession; it’s the price of a floor that doesn’t freeze your feet.
And the real heating of the duo, the one that makes everything else secondary, is geography. We go south before the real rains from the north and come back in spring. A heater that we don’t turn on is a heater that doesn’t break down, consumes nothing, and doesn’t create condensation. That’s the whole subject of our article on winter in the sun.
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Read moreThe coldest we’ve experienced, and the irony of the situation
The question comes up all the time: what’s your worst memory of cold? The answer is almost too good. The coldest we’ve had was during the clutch failure in Spain, in January 2022, precisely because we couldn’t turn on the heating. We were really cold, and it wasn’t Truma’s fault.
I’m not recounting the episode here; it’s fully detailed in our maintenance cost report. What I take away from it for this article is that the cold experienced in a motorhome is almost never a heating problem. It’s a situational problem.
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Read moreWaking up in Switzerland, no water at the tap
Another time, in Switzerland, a very cold wake-up and not a drop at the tap. Total incomprehension, a few minutes searching, and the discovery: the water had escaped from underneath the motorhome. It wasn’t a failure. It was a safety feature that had done exactly its job.
Where to place your carbon monoxide detector
Yes, we have one. And it goes off quite often while cooking. Not because we’re close to an accident, but because it’s placed very close to the stove, and a dish that’s a bit too grilled is enough to trigger it.
I prefer to share this rather than give you an alarmist paragraph because the real risk is there. A poorly placed detector cries wolf, and a detector that you end up ignoring is worse than having no detector at all. The day it goes off for the right reason, your first reaction will be to open the window with a sigh.
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Read moreTwo things to get right. The alarm itself: for a vehicle you want one to BS EN 50291-2, the version written for recreational vehicles, not a house alarm borrowed from the hallway, because the vibration, the temperature swings and the damp are a different world. And the placement: carbon monoxide has a density close to air, it diffuses through the whole volume, so it goes at breathing height, on the sleeping side, between one and three metres from any possible source and never directly above a cooking appliance, which is exactly the mistake we made. Not in a dead corner, not behind a curtain, not in a cupboard. And while we’re at it, a detector never replaces a functioning ventilation system: that’s the subject of our article on high and low ventilation, and on a gas vehicle, these grills should never be blocked for any reason, even in winter.
Camper van heating: what we're still being asked
Can you leave a Truma gas heater running while driving?
A gas heater can operate while driving provided that the installation allows it and that a safety device cuts off the supply in case of a shock. On many older vehicles, this device does not exist, and the question does not even arise. The healthy reflex on a vehicle of this age is to turn off the gas at the bottle tap before hitting the road, and to relight it upon arrival.
My Truma is going into safety mode and won't turn on, where should I start?
In order, and that solves the vast majority of cases. The gas first: bottle tap open, bottle not empty, regulator that hasn't triggered its safety. The ignition next, which in older generations works with dedicated batteries: tired batteries produce a spark that is too weak and the burner won't ignite. The draft finally: the flue must be clear, a nest or a leaf is enough to put the device out of order. If all three are good, it's the solenoid valve or the probe, and that's where the workshop comes in.
Does an electric space heater work with a camping socket?
Rarely, and this is the classic trap. Camping terminals are often calibrated to 6 or 10 amps, sometimes 16, which is around 1,400 to 2,300 watts for the entire vehicle. An additional 2,000 watts therefore consumes almost all that the terminal accepts, and the circuit breaker trips as soon as the water heater or kettle starts at the same time. An electric supplement only makes sense at low power, at 500 or 800 watts, and as a real supplement, not as the main heating source.
Does a carbon monoxide detector expire?
Yes, and this is the one nobody checks. A CO alarm has a stated life, usually seven to ten years, printed on the back with a replace-by date: the electrochemical cell degrades whether it has ever seen carbon monoxide or not. Press-to-test only proves the buzzer works, never that the sensor still does. For a vehicle, buy one certified to BS EN 50291-2, the recreational-vehicle version of the standard, and write the replace-by date somewhere you will actually look.
Does heating dry out the air or worsen condensation?
A forced air heater dries the ambient air, which is even part of its appeal in winter. But it doesn't make water disappear; it displaces it: warm air carries more moisture, and this moisture condenses as soon as it touches a cold surface, such as windows, window frames, and uninsulated corners. Heating without ventilation means creating condensation elsewhere. You need both.
Butane or propane for heating in winter?
Propane, without hesitation, and for a purely physical reason: butane stops vaporizing properly when the temperature approaches zero, so the bottle stops delivering gas at the precise moment you need it most. Propane continues to work well below zero. That's the only real difference that matters when it comes to heating.
Should you close the warm air vents that you are not using?
No, not all of them. Closing one or two vents redirects the airflow to the others and can actually heat the living area better. But closing everything except one puts the fan under pressure, increases noise, and makes the unit operate in conditions for which it was not designed. The right setting is to direct the airflow, not to strangle it.
What do we do with the water heater when the vehicle sleeps all winter?
We empty it and leave the drain valve open during the entire downtime. A boiler left full in an unheated vehicle means water that freezes, expands, and cracks the tank. A cracked water heater cannot be repaired; it must be replaced, and it is one of the most expensive items in the unit.
Are spare parts still available for a Truma heater that is over twenty years old?
For wear parts, yes, and this is one of the reasons for the longevity of these devices: consumables, igniters, probes, seals, and thermocouples are still distributed and often shared between several generations. What becomes difficult to find are the electronic controls and specific control panels. A periodic review by an approved workshop, about every two years, remains the best investment for a device of this age.
What heating system to choose in a converted van that has nothing?
The real criterion is not comfort, it's what you already have on board. If the vehicle already has gas for cooking and hot water, a gas combination unit shares the energy and avoids adding a second circuit. If you aim for a vehicle without gas at all, a diesel connected to the engine tank is more coherent, provided you accept the noise and the electrical consumption of the fan. The worst choice is to combine both energies for occasional use.
Van life day to day, unfiltered
Two years of full-time van life, and the Algarve as our base ever since. We still hit the road, by van or otherwise, and we write up what we find along the way. An email when we have something to say, no more.
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